SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '2a1bd7b45fcbc61fc9f0bba38bebdc93075d20a6b5347990df13627dc6be9083' 
  AND token = 'AP+RmLw1ezDQsaR4J53C/xXXvMXTgv1fLOMydVW1O24=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}